The present study is a dose effect study designed to test for the safety and efficacy of E1-deleted recombinant adenovirus containing the CFTR cDNA under a CMV-beta actin promoter in CF nasal epithelia. The goal is to define the safety and efficacy of the various doses as a function of time, with the ultimate goal of using these studies to understand safety, efficacy, and potential dosing intervals pertinent to this novel therapy.